    :root {
            --primary-color: #4e73df;
            --secondary-color: #858796;
            --success-color: #1cc88a;
            --info-color: #36b9cc;
            --warning-color: #f6c23e;
            --danger-color: #e74a3b;
            --light-color: #f8f9fc;
            --dark-color: #5a5c69;
        }

        body {
            background-color: #f8f9fc;
            font-family: 'Nunito', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
        }

        .navbar {
            background-color: #fff;
            box-shadow: 0 0.15rem 1.75rem 0 rgba(58, 59, 69, 0.15);
        }

        .navbar-brand {
            font-weight: 800;
            color: var(--primary-color);
        }

        .card {
            border: none;
            border-radius: 0.35rem;
            box-shadow: 0 0.15rem 1.75rem 0 rgba(58, 59, 69, 0.15);
        }

        .card-header {
            background-color: #f8f9fc;
            border-bottom: 1px solid #e3e6f0;
            padding: 1rem 1.25rem;
        }

        .btn-primary {
            background-color: var(--primary-color);
            border-color: var(--primary-color);
        }

        .btn-primary:hover {
            background-color: #2e59d9;
            border-color: #2653d4;
        }

        .form-control:focus {
            border-color: #bac8f3;
            box-shadow: 0 0 0 0.2rem rgba(78, 115, 223, 0.25);
        }

        .alert {
            border: none;
            border-radius: 0.35rem;
        }

        .table {
            margin-bottom: 0;
        }

        .table th {
            border-top: none;
            background-color: #f8f9fc;
            color: var(--secondary-color);
            font-weight: 700;
            text-transform: uppercase;
            font-size: 0.7rem;
            letter-spacing: 0.1rem;
        }

        .content {
            flex: 1;
            padding-bottom: 100px; /* 为页脚留出更多空间 */
        }

        .footer {
            position: relative;
            width: 100%;
            padding: 25px 0;
            background-color: #f8f9fa;
            text-align: center;
            margin-top: auto;
            border-top: 1px solid #e3e6f0;
            box-shadow: 0 -0.15rem 1.75rem 0 rgba(58, 59, 69, 0.15);
        }

        .but {
            text-decoration: none;
            padding: 8px 15px;
            border-radius: 5px;
            font-size: 14px;
            display: inline-block;
            margin: 0 8px;
            transition: all 0.3s ease;
        }

        .but:hover {
            transform: translateY(-2px);
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
        }

        .c-blue {
            color: #0d6efd;
            background-color: rgba(13, 110, 253, 0.1);
        }

        .c-red {
            color: #dc3545;
            background-color: rgba(220, 53, 69, 0.1);
        }

        .c-yellow {
            color: #ffc107;
            background-color: rgba(255, 193, 7, 0.1);
        }

        .ml10 {
            margin-left: 15px;
        }